The present invention relates to an apparatus for forming a blended yarn from a plurality of yarn strands.
In the manufacture of a blended yarn from two or more multi-filament yarn strands of different colors or dyeability, it is known to supply the individual strands to a common take-up bobbin such that the strands advance in a parallel side by side arrangement to the take-up bobbin and are wound thereon. This process however often leads to the presence of unsightly streaks in the fabric produced from the resulting blended yarn. It is also known that such streaks can be avoided or at least reduced by periodically changing the relative arrangement of the individual yarn strands in short time intervals as they are advanced to the take-up bobbin.
A prior attempt to reduce unsightly streaks of the described type is disclosed in EP 0 133 198 A2, which relates to a method of making an untwisted crimped yarn from at least two yarn strands of different color and dyeability. The process disclosed in this application is intended to prevent unsightly streaks in that at least one of the yarn strands is alternately moved to opposite sides of another of the yarn strands. To effect such movement, traversing yarn guides or slotted drums are proposed. However, these disclosed embodiments involve considerable expenditure, and impart a substantial stress to the individual yarn strands. Likewise, the threading of the yarn strands on the drawing and texturizing machines subsequent to the yarn shifting device has caused problems for the operating personnel.
It is accordingly an object of the present invention to provide an apparatus and method for forming a blended yarn from a plurality of yarn strands which avoids the limitations and disadvantages of the prior processes noted above.
It is a more particular object of the present invention to provide an apparatus and method of the described type which includes a simple and yarn protecting apparatus for laterally displacing the individual yarn strands.